Coreference resolution is the task of delineating and grouping together referring expressions in text so that spans of text referring to the same discourse entity are clustered together. The past decade has seen remarkable improvements in the consistency and performance of coreference resolution, first through the creation of large (\(>\) 1 M tokens) benchmark data in OntoNotes ([1]}, [2]}; hence ON), and then through use of that dataset in the CoNLL shared task on coreference resolution [3]} and the development of evaluation metrics ([4]}; see [5]} for criticism). With the advent of end-to-end neural approaches to coreference resolution [6]}, we have seen scores on coreference resolution rise from the mid-50s at the 2011 shared task to current SOTA scores around 80 points when gold speaker information is provided [7]}, [8]}, as evaluated by the standard metrics on the ON test set.
